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Published on Leave a comment on Nonprescription Cold Meds That Don’t Work

When suffering from cold symptoms or acute sinusitis, there are some products that work for nasal congestion, and thick phlegm and mucus. Mucinex works well for thick phlegm and mucus, and Sudafed containing pseudoephedrine works for nasal congestion. However, that Sudafed is behind the pharmacy counter, can only be bought in limited quantities, and one must show a driver's license and sign for it before getting any. There are also many other easily available nonprescription cold products containing phenylephrine. But this latest research shows clearly that products containing phenylephrine don't work at any dose. Bottom line: when buying a decongestant, get the stuff containing pseudoephedrine that is behind the pharmacy counter. From Forbes:

The Popular Over-The-Counter Cold Medicine That Science Says Doesn't Work

The market for over-the-counter cold medicines is worth $8 billion annually, with a hefty portion of that amount spent on drugs marketed as decongestants....According to University of Florida researchers, the oral decongestant phenylephrine simply doesn’t work at the FDA-approved amount found in popular non-prescription brands, and it may not even work at much higher doses. Their conclusions were presented in an editorial in The Journal of Allergy and Clinical Immunology: In Practice....

The study of 539 adults lasted one week and failed to find a dose of phenylephrine within the 10 mg to 40 mg range that was more effective than a placebo in relieving nasal congestion. The approved Food and Drug Administration (FDA) dose is 10 mg every four hours for “temporary relief of nasal congestion.” Consequently, the UF researchers are asking the FDA to remove oral phenylephrine from the market.

“We think the evidence supports that phenylephrine’s status as a safe and effective over-the-counter product should be changed,” said Randy Hatton, Pharm.D., a clinical professor of pharmacotherapy and translational research. “We are looking out for the consumer, and he or she needs to know that science says that oral phenylephrine does not work for the majority of people.”

Back before methamphetamine cooks started buying up non-prescription decongestants to brew crank, all of us were able to buy effective decongestants right off the store shelf without a problem. The active ingredient in those meds, coveted by meth smurfers and cold sufferers alike, was pseudoephedrine. But then federal legislation was enacted to restrict the sale of pseudoephedrine-containing products (Combat Methamphetamine Epidemic Act of 2005) and they were moved behind the pharmacy counter. You can still buy them, assuming you know they’re available, by presenting identification and signing a statement saying you’re not buying the drugs for nefarious purposes.

To fill the store-shelf void, drug companies substituted the already-FDA approved ingredient phenylephrine for pseudoephedrine. Several studies testing phenylephrine against a placebo produced results that question its effectiveness, and eventually the FDA started to at least listen to critics in the research community asking for greater scrutiny. The latest research adds a boldface exclamation point to the criticism. Whether the FDA will choose to act on the findings is another matter, but the science is there.

The number of brands containing phenylephrine are too many to list, but the majority of on-the-shelf oral decongestants list it as an active ingredient, including many multi-symptom products. Instead of buying products containing phenylephrine, the researchers suggest cold and allergy sufferers choose a pseudoephedrine product from behind the counter or nasal steroids for allergic rhinitis.

Published on Leave a comment on Little Is Known About the Viruses Living On Healthy Skin

The microbes living on healthy human skin include bacteria, fungi, and viruses...but 90% of the viruses found on healthy skin in this study are unknown to researchers - thus "viral "dark matter". The skin virome  is the population of viruses on the skin. It turns out that most of the viruses on healthy skin are phage viruses. called bacteriophages.They infect bacteria and may take up residence within bacteria. From Science Daily:

90 percent of skin-based viruses represent viral 'dark matter,' scientists reveal

Scientists in recent years have made great progress in characterizing the bacterial population that normally lives on human skin and contributes to health and disease. Now researchers from the Perelman School of Medicine at the University of Pennsylvania have used state-of-the-art techniques to survey the skin's virus population, or "virome." The study, published in the online journal mBio last month, reveals that most DNA viruses on healthy human skin are viral "dark matter" that have never been described before. The research also includes the development of a set of virome analysis tools that are now available to researchers for further investigations.

Researchers and the public are increasingly aware that microbes living on and inside us -- our "microbiomes" -- can be crucial in maintaining good health, or in causing disease. Skin-resident bacteria are no exception. Ideally they help ward off harmful infections, and maintain proper skin immunity and wound-healing, but under certain circumstances they can do the opposite.

"Until now, relatively little work has been done in this area, in part because of the technical challenges involved. For example, a skin swab taken for analysis will contain mostly human and bacterial DNA, and only a tiny amount of viral genetic material -- the proverbial needles in the haystack." 

Their analysis of samples from 16 healthy individuals revealed some results that were expected. The most abundant skin-cell infecting virus was human papilloma virus, which causes common warts and has been linked to skin cancers. However, most of the detected DNA from the VLPs did not match viral genes in existing databases. "More than 90 percent was what we call viral dark matter -- it had features of viral genetic material but no taxonomic classification," Grice said. That came as a surprise, although of course it highlighted the importance of mapping this unexplored territory.

The findings also clearly linked the skin virome to the skin microbiome: Most of the detected viral DNA appeared to belong to phage viruses, which infect and often take up long-term residence within bacteria. And when Grice and colleagues sequenced skin bacterial DNA from the same 16 subjects, they found that it often contained tell-tale marks -- called CRISPR spacers -- of prior invasion by the same phage viruses.

The results also showed that the skin virome varies considerably depending on the body site. Grice's team took swabs from the palm, the forehead, the armpit, the navel, and other sites, and found, for example, that the virome was most diverse in the crook of the arm, a site that is intermittently exposed and occluded.

Published on Leave a comment on Exposure to Animals In First Year of Life and Lower Risk of Asthma

Labrador Retriever image Other studies have found this same association - that living with a dog or farm animal has health benefits such as lower risk of allergies and asthma. In a Swedish nationwide study looking at over a million children, the association between early exposure to dogs and farm animals and the risk of asthma was evaluated. All children born in Sweden from January 1, 2001, to December 31, 2010 were included. The researchers found that exposure to dogs and farm animals during the first year of life reduces the risk of asthma in children at age 6 years. From Science Daily:

Early contact with dogs linked to lower risk of asthma

A team of Swedish scientists have used national register information in more than one million Swedish children to study the association of early life contact with dogs and subsequent development of asthma. This question has been studied extensively previously, but conclusive findings have been lacking. The new study showed that children who grew up with dogs had about 15 percent less asthma than children without dogs.

A total of more than one million children were included in the researchers' study linking together nine different national data sources, including two dog ownership registers not previously used for medical research...."Earlier studies have shown that growing up on a farm reduces a child's risk of asthma to about half. We wanted to see if this relationship also was true also for children growing up with dogs in their homes. Our results confirmed the farming effect, and we also saw that children who grew up with dogs had about 15 percent less asthma than children without dogs.

"These kind of epidemiological studies look for associations in large populations but do not provide answers on whether and how animals could protect children from developing asthma. We know that children with established allergy to cats or dogs should avoid them, but our results also indicate that children who grow up with dogs have reduced risks of asthma later in life. Thanks to the population-based design, our results are generalizable to the Swedish population, and probably also to other European populations with similar culture regarding pet ownership and farming" says Catarina Almqvist Malmros, senior author on the study, Paediatrician at Astrid Lindgren Children's Hospital and Professor in Clinical epidemiology at Dept of Medical Epidemiology and Biostatistics at Karolinska Institutet, Stockholm.

Published on Leave a comment on Time to Ditch Personal Care Products Containing Parabens?

Even though many, many personal care products contain parabens, the evidence is accumulating that parabens have negative health effects. And now research suggesting that perhaps they may be a factor in developing breast cancer. This latest study was done "in vitro" - meaning looking at the effects of chemicals on human breast cells (in culture dishes), but the results absolutely should make someone think twice about all the parabens in products, and how they accumulate in us. Research has already found parabens in the human breast, but many thought that the levels were too low to promote cancer.

Parabens are common ingredients in cosmetics, shampoos, body lotions and sunscreens, where they are used to prevent microbial growth and prolong shelf life.  Common names of parabens are: methylparaben, ethylparaben, propylparaben, and butylparaben. Detectable levels of multiple parabens are present in human urine and breast tissue. Bottom line: Parabens are endocrine disrupting chemicals that mimic estrogens and may have effects at very low doses to stimulate breast cancer cell growth. So read labels of personal care products and avoid those with parabens. From Futurity:

New Tests Suggest Parabens Carry Cancer Risk

A group of chemicals called parabens—common ingredients in personal care products—may interact with growth factors in the body to increase the risk of breast cancer, according to new research. Parabens are preservatives widely used in everything from shampoos and cosmetics to body lotions and sunscreens. The chemicals have generated increasing health concerns, however, because they mimic estrogens, which have been linked to an increased risk of breast cancer and reproductive problems.

“Although parabens are known to mimic the growth effects of estrogens on breast cancer cells, some consider their effect too weak to cause harm,” says lead investigator Dale Leitman, a gynecologist and molecular biologist at the University of California, Berkeley, and an adjunct associate professor of nutritional sciences and toxicology. “But this might not be true when parabens are combined with other agents that regulate cell growth.”

Existing chemical safety tests, which measure the effects of chemicals on human cells, look only at parabens in isolation, he says. They fail to take into account that parabens could interact with other types of signaling molecules in the cells to increase breast cancer risk.

To better reflect what goes on in real life, Leitman and his colleagues looked at breast cancer cells expressing two types of receptors: estrogen receptors and HER2. Approximately 25 percent of breast cancers produce an abundance of HER2, or human epidermal growth factor receptor 2. HER2-positive tumors tend to grow and spread more aggressively than other types of breast cancer.

The researchers activated the HER2 receptors in breast cancer cells with a growth factor called heregulin that is naturally made in breast cells, while exposing the cells to parabens. Not only did the parabens trigger the estrogen receptors by turning on genes that caused the cells to proliferate, but also the effect was significant. The parabens in the HER2-activated cells were able to stimulate breast cancer cell growth at concentrations 100 times lower than in cells that were deprived of heregulin.

The study demonstrates that parabens may be more potent at lower doses than previous studies have suggested, which may spur scientists and regulators to rethink the potential impacts of parabens on the development of breast cancer, particularly on HER2 and estrogen receptor positive breast cells. The findings also raise questions about current safety testing methods that may not predict the true potency of parabens and their effects on human health.

Published on

According to a new report, it looks like most people under the age of 50 (throughout the world) have herpes simplex virus infections - whether type 1 or type 2. (Picture is of a herpes simplex virus type 1, at www.virology.net). From Medical Xpress:

An estimated two-thirds of world's population under age of 50 are infected with herpes simplex virus type 1

More than 3.7 billion people under the age of 50 are infected with herpes simplex virus type 1 (HSV-1), which commonly causes 'cold sores' and can also cause genital herpes, according to new research by the University of Bristol and the World Health Organisation [WHO]. The findings, published in the journal PLOS ONE, reveal the first global estimates of HSV-1 infection.

Herpes simplex virus is categorised into two types: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). Both HSV-1 and HSV-2 are highly infectious and incurable. HSV-1 is primarily transmitted by oral-oral contact and in many cases causes orolabial herpes or "cold sores" around the mouth. HSV-2 is almost entirely sexually transmitted through skin-to-skin contact, causing genital herpes. 

The new estimates highlight, however, that HSV-1 is also an important cause of genital herpes. Some 140 million people aged 15-49 years are estimated to be infected with genital HSV-1 infection, primarily in the Americas, Europe and Western Pacific. Earlier this year, WHO published estimates of herpes simplex virus type 2 (HSV-2) infection showing that an estimated 417 million people between 15-49 years of age have infection caused by HSV-2. Taken together, these estimates suggest that over half a billion people between 15-49 years of age have a genital infection due either to HSV-1 or HSV-2. This highlights the large global burden of genital herpes caused by both HSV types.

Given the lack of a permanent and curative treatment for both HSV-1 and HSV-2, WHO and partners are working to accelerate development of HSV vaccines and topical microbicides, which will have a crucial role in preventing these infections in the future. Several candidate vaccines and microbicides are currently being studied. 

Published on Leave a comment on Report Says Mammograms Haven’t Reduced Rate Of Metastatic Cancer

A report by 3 prominent specialists (including Gilbert Welch - who has been discussed in earlier posts) about trends in metastatic breast and prostate cancer came out today in the New England Journal of Medicine. The biggest finding was that mammograms have not cut the rate of metastatic breast cancer. Mammography screening is based on the hope that cancer that is detected in an early, localized phase can then be treated more easily and that it would reduce the numbers of metastastic cancers (that spread to lymph nodes and to more distant organs) that eventually kill. However, this has not happened.The incidence of metastatic breast cancer has been stable since 1975, and the average age of diagnosis among women older than 40 is still 63.7 years . The authors theorize that "breast cancer is a systemic disease by the time it's detectable". From Medical Xpress:

Study: Mammograms haven't cut rate of advanced breast cancer

A new report raises fresh questions about the value of mammograms. The rate of cancers that have already spread far beyond the breast when they are discovered has stayed stable for decades, suggesting that screening and early detection are not preventing the most dangerous forms of the disease. The report, in Thursday's New England Journal of Medicine, is by three prominent cancer specialists and is based on federal statistics going back to the 1970s.

"We're undergoing what I think for the public is a very confusing debate" about screening, but it's really "a course correction" prompted by more awareness of its risks and benefits to various groups of women, said Dr. H. Gilbert Welch, a health policy expert at Dartmouth Medical School. "All they heard for years was, 'there are only benefits.'" He is the lead author of the report, co-written with Dr. David Gorski of Wayne State University School of Medicine in Detroit and Dr. Peter Albertsen of the University of Connecticut Health Center in Farmington.

"Screening offers hope that cancer can be detected in an early, localized phase when it's more amenable to treatment," they write, but that assumes that cancer starts in one place, grows and then spreads. If that was always true, screening would reduce the rate of advanced cancers. And that has not happened. The rate of breast cancers detected at an advanced stage has been stable since 1975, despite wide use of mammography since the 1980s. The average age of women diagnosed with cancer also has remained around 63, another sign cancers are not being found sooner.

The trends suggest that some breast cancers are already "systemic" or widely spread from the start, and that finding them sooner has limited impact. "Screening mammography has been unable to identify those bad cancers, destined to become metastatic, at an earlier stage. That doesn't say mammography doesn't help less aggressive cancers," but those are less likely to prove deadly, Welch said.

Dr. Barnett Kramer, a screening expert at the National Cancer Institute, said the report shows the limitations of mammography. "I wouldn't want to say it has had no effect but it certainly has not lived up to the anticipated effect," he said. For every tumor detected early because of mammography, "you would hope to see ... an equal reduction in metastatic disease, and that has not occurred."

The situation is very different with prostate cancer. The rate of advanced cases of that disease has been cut in half since screening with PSA blood tests came into wide use around 1988, and the average age at which men are diagnosed has fallen—from 72 to 70, the authors write. However, this does not prove PSA testing is good. Shifting the stage at which a disease is diagnosed is "only the first step for successful screening," which also has to save lives to be worthwhile, Welch said. "Just because you find something earlier doesn't mean you can change its course."

Again, Kramer agreed. Prostate screening, "when put to a definitive test, did not show a clear reduction in prostate cancer mortality" in large, rigorously done trials, he said. The government task force recommends against PSA testing, and says its risks outweigh its benefits for most men.

"Screening is a close call," Welch said. "My guess is few people are helped" by prostate or breast cancer screening while many are harmed by false alarms that trigger unnecessary tests and treatments, he said.

The original report, which also includes a discussion on prostate cancer and the PSA test, in the New England Journal of Medicine:  Trends in Metastatic Breast and Prostate Cancer — Lessons in Cancer Dynamics

Published on Leave a comment on Reducing Sugar Improves Health

This study showed that children reducing sugar consumption (but not fruits), and without reducing calories, after 10 days improved all sorts of metabolic health markers: blood pressure, LDL cholesterol, triglycerides, liver function, fasting blood glucose, and insulin levels. As one of the researchers said: "I have never seen results as striking or significant in our human studies; after only nine days of fructose (sugar) restriction, the results are dramatic and consistent from subject to subject." Once again, not all calories are the same.

On average, the obese children in this study had been getting about 27 percent of their daily calories from sugar, and during the study period it was lowered to about 10 percent of daily calories. By comparison, the average American takes in about 15 percent, though children typically consume much more than this in part because they have the highest intake of sugar-sweetened beverages. In February of this year, the federal government’s Dietary Guidelines Advisory Committee recommended that Americans limit their intake of added sugars to no more than 10 percent of daily calories. From Medical Xpress:

Obese children's health rapidly improves with sugar reduction unrelated to calories

Reducing consumption of added sugar, even without reducing calories or losing weight, has the power to reverse a cluster of chronic metabolic diseases, including high cholesterol and blood pressure, in children in as little as 10 days, according to a study by researchers at UC San Francisco and Touro University California.

"This study definitively shows that sugar is metabolically harmful not because of its calories or its effects on weight; rather sugar is metabolically harmful because it's sugar," said lead author Robert Lustig, MD, MSL, pediatric endocrinologist at UCSF Benioff Children's Hospital San Francisco. "This internally controlled intervention study is a solid indication that sugar contributes to metabolic syndrome, and is the strongest evidence to date that the negative effects of sugar are not because of calories or obesity."

Metabolic syndrome is a cluster of conditions—increased blood pressure, high blood glucose level, excess body fat around the waist, and abnormal cholesterol levels—that occur together and increase risk of heart disease, stroke, and diabetes. Other diseases associated with metabolic syndrome, such as non-alcoholic fatty liver disease and type 2 diabetes, now occur in children—disorders previously unknown in the pediatric population.

In the study, 43 children between the ages of 9 and 18 who were obese and had at least one other chronic metabolic disorder, such as hypertension, high triglyceride levels or a marker of fatty liver, were given nine days of food, including all snacks and beverages, that restricted sugar but substituted starch to maintain the same fat, protein, carbohydrate, and calorie levels as their previously reported home diets.....The study menu restricted added sugar (while allowing fruit), but substituted it by adding other carbohydrates such as bagels, cereal and pasta so that the children still consumed the same number of calories from carbohydrate as before, but total dietary sugar was reduced from 28 to 10 percent, and fructose from 12 to 4 percent of total calories, respectively. The food choices were designed to be "kid food" - turkey hot dogs, potato chips, and pizza all purchased at local supermarkets, instead of high sugar cereals, pastries, and sweetened yogurt.

Children were given a scale and told to weigh themselves everyday, with the goal of weight stability, not weight loss. When weight loss did occur (a decrease of an average of 1 percent over the 10-day period but without change in body fat), they were given more of the low-sugar foods."When we took the sugar out, the kids started responding to their satiety cues," said Schwarz. "They told us it felt like so much more food, even though they were consuming the same number of calories as before, just with significantly less sugar. Some said we were overwhelming them with food."

After just 9 days on the sugar-restricted diet, virtually every aspect of the participants' metabolic health improved, without change in weight. Diastolic blood pressure decreased by 5mm, triglycerides by 33 points, LDL-cholesterol (known as the "bad" cholesterol) by 10 points, and liver function tests improved. Fasting blood glucose went down by 5 points, and insulin levels were cut by one-third. "All of the surrogate measures of metabolic health got better, just by substituting starch for sugar in their processed food—all without changing calories or weight or exercise," said Lustig. "This study demonstrates that 'a calorie is not a calorie.' Where those calories come from determines where in the body they go. Sugar calories are the worst, because they turn to fat in the liver, driving insulin resistance, and driving risk for diabetes, heart, and liver disease."

Published on Leave a comment on Secret Hazard of Nail Polish

Beware of nail polish because it may be contaminating your body with an endocrine disrupting chemical.  A study co-authored by researchers at Duke University and Environmental Working Group (EWG) detected evidence of a common nail polish chemical called triphenyl phosphate, or TPHP, in the bodies of every woman who volunteered to paint her nails for the study.There is growing evidence suggesting that TPHP may affect hormone regulation, metabolism, reproduction and development. Unfortunately, even if it is not listed on the label, it may still be in the product. It is also used as a fire retardant (and the evidence from studies says to avoid fire retardants). Go to the EWG site for more on nail polish brands.From Environmental Working Group (EWG):

Duke-EWG Study Finds Toxic Nail Polish Chemical In Women’s Bodies

Researchers at Duke University and Environmental Working Group have found evidence of a suspected endocrine-disrupting chemical widely used in popular nail polishes in the bodies of more than two-dozen women who participated in a biomonitoring study. The study, published today in Environment International, found that all women had a metabolite of triphenyl phosphate, or TPHP, in their bodies just 10 to 14 hours after painting their nails. Their levels of diphenyl phosphate or DPHP, which forms when the body metabolizes TPHP, had increased by nearly sevenfold.

According to EWG’s Skin Deep® cosmetics database, more than 1,500 nail products including polishes made by Sally Hansen, OPI and Wet N Wild, contain TPHP. Click here for a list of brands that list TPHP as an ingredient. More nail polishes may contain undisclosed TPHP.  The Duke-EWG study tested 10 polishes for TPHP and found the chemical in eight of them. Two of the eight with TPHP did not list the ingredient on their labels.  ...continue reading "Secret Hazard of Nail Polish"

Published on Leave a comment on Chemicals Remain On New Clothes

Research for a doctoral thesis found that thousands of chemicals (from manufacturing the textiles and clothes) remain on finished clothes, and many of these remain after washing. Bottom line: wash new clothes before wearing! From Science Daily:

Toxins remain in your clothes

Thousands of chemicals are used in clothes manufacturing. Researchers at Stockholm University have examined if there are chemicals in the clothes we buy as well. Several substances related to health risks were identified and not even organic cotton was a guarantee for non-toxic textiles. In a new thesis 60 garments from Swedish and international clothing chains have been tested. An initial analysis found thousands of chemicals in the clothes and around a hundred chemicals were preliminary identified. Several of the substances were not on the producers' lists and are suspected to be by-products, residues or chemicals added during transport.

"Exposure to these chemicals increases the risk of allergic dermatitis, but more severe health effect for humans as well as the environment could possibly be related to these chemicals. Some of them are suspected or proved carcinogens and some have aquatic toxicity," says Giovanna Luongo, PhD in Analytical Chemistry at Stockholm University.

Depending on occurrence, quantity, toxicity and how easily they may penetrate the skin, four groups of substances were chosen for further analysis. The highest concentrations of two of these, quinolines and aromatic amines, were found in polyester. Cotton contained high concentrations of benzothiazoles, even clothes made from organic cotton.

The researchers washed the clothes and then measured the levels of chemicals. Some of the substances were washed off, with a risk of ending up in aquatic environments. Others remained to a high degree in the clothes, becoming a potential source of long-term dermal exposure. It is difficult to know if the levels of these harmful substances are hazardous, and what effects chemicals in our clothes can have in the long run.

Published on

Another study providing evidence that the Mediterranean diet is good for the brain. In elderly dementia-free adults (mean age 80 years) - those that generally followed a Mediterranean diet (higher adherence) had a larger brain volume than those not following the Mediterranean diet, as well as more total gray and white matter volume.The difference between the groups is equal to about 5 years of aging.

Having "higher adherence to the Mediterranean diet" in the study meant higher consumption of healthy foods or lower consumption of unhealthy foods. The Mediterranean diet stresses a  high intake of vegetables, legumes, fruits, whole grains, fish, olive oil, and low intake of saturated fatty acids, dairy products, meat, and poultry; and mild to moderate amounts of alcohol. Specifically: Higher fish intake (at least 3 to 5 oz. weekly) and lower meat intake (no more than 3.5 oz. daily) correlated with greater total gray matter volume. Higher fish intake was also associated with "greater mean cortical thickness". From Medical Xpress:

Mediterranean diet may keep your mind healthier in old age

In news that sounds a bit like it came straight from a sci-fi thriller, researchers say that eating too much meat might shrink your brain. On the flip sid e, however, eating healthy foods from the so-called Mediterranean diet may help your brain stay in good shape as you get older, the new study suggests. The researchers said that people over 65 who ate more fish, vegetables, fruit, grains and olive oil had a larger brain volume than a similar group who didn't follow a Mediterranean diet.

"It was encouraging to see that the more you adhere to this Mediterranean diet, the more protection you get against brain atrophy [shrinkage]," said study author Yian Gu, an assistant professor of neuropsychology at Columbia University in New York City. .... But Gu noted that her study's observational findings cannot prove a definitive cause-and-effect relationship between diet and brain volume. The study was only designed to find an association.

Previous research has linked the Mediterranean diet to a lower risk of Alzheimer's disease, the study said. The diet stresses the consumption of vegetables, legumes (beans, peas and lentils), fruits, cereals, fish and monounsaturated fats such as olive oil, the study authors said. The eating plan also includes a low intake of meat, poultry, saturated fats and dairy products, as well as mild to moderate amounts of alcohol, according to the researchers.

For the study, Gu and her colleagues split 674 adults into two groups based on how closely their diets aligned with the Mediterranean diet. Their average age was 80 years. All participants underwent MRI scans of their brains to measure total brain volume and thickness. They also completed questionnaires about their food choices and eating patterns.

The researchers found that brain volumes of those who didn't follow a Mediterranean diet were smaller than those who did. The difference was minor in overall size—equated to about five years of aging, the study authors said. But, more specifically, the investigators found that eating more fish and less meat was associated with even less brain shrinkage. Using the study findings, Gu contended that eating at least 3 to 5 ounces of fish weekly, or no more than 3.5 ounces of meat each day, could protect the brain from shrinkage. She acknowledged that study participants may have inaccurately recalled their food consumption habits in the questionnaires used.